Where the Willis name comes from

Willis is a surname of English, Norman French and Scottish origin, and it grew from more than one unrelated root. The plainest root is a patronymic from Will, the short form of William, so the name first meant son of Will. In Scotland especially, it developed from Wills and follows the same pattern as Wilson. William stayed so popular after the Norman Conquest that many families named Willis are not related at all, even distantly.

A second line runs back to the de Welles family, Lincolnshire nobles whose name came from the Norman de Vallibus, meaning of the valley. That Norman name traces to the Vaux family, established in England by Harold de Vaux, a close relative of William the Conqueror. The oldest surviving family of the name, the Willes family of Warwickshire, appears in records from 1330 under the spellings Willis, Willys and Wyllys.